1. Field of the Invention
The present invention relates generally to apparatus for flow conducting devices, and more particularly but not by way of limitation, to a dripless coupling device for quick connection and disconnection of flow conducting members in the use of liquid herbicides and the like.
2. Brief Description of the Related Art
Herbicides play a dominant role in the control of unwanted plant growth in modern agribusiness. Historically, farmers have had unlimited access to herbicides in various kinds of packaging such as small metal cans. Due to environmental considerations, modes of distribution are increasingly regulated and restricted for toxic substances such as herbicides. Farmers must often store a large volume of herbicide in a tank prior to use in order to comply with regulations. The present invention is intended to aid the farmer connect herbicide vessels in a quick fashion with minimal efficiency while assuring substantially dripless fluid transfer.
None of the prior art specifically teaches applications for herbicide dispensing systems. Most of the art, like the present invention, has general application in connecting members which conduct fluid flow. Much of the art was developed in the 1940s in the context of airplane fueling systems.
Main, U.S. Pat. No. 2,457,251 issued Dec. 28, 1948, and Fisher, U.S. Pat. No. 2,254,997 issued Sept. 2, 1941, are two representative patents from that era. A problem that neither patent resolves is port indexing, i.e. the ports of the coupling members are not indexed, therefore the flow axis is obstructed by the internal apparatus of the invention. Also, neither patent effectively addresses the problem of leakage during engagement and disengagement. Finally, the problem of internal fluid pressure buildup due to repeated engagement and disengagement with fluid in the apparatus is not addressed.
French Patent No. 1,120,330 addressed the matter of port indexing but was not concerned with dripless connecting disconnecting as required for herbicide dispensing.